A land calculator for Magic: The Gathering decks
Try it out at https://gpofcher.github.io/landcalc/
Based on Analysis by Frank Karsten: https://www.channelfireball.com/article/how-many-lands-do-you-need-in-your-deck-an-updated-analysis/cd1c1a24-d439-4a8e-b369-b936edb0b38a/